Extraction Of Allelochemicals From Eucalyptus APMP Effluents And Its Inhibition On Microcystis Aeruginosa Growth

Eutrophication is a common problem currently in water environment.Algae outbreaks caused by eutrophication,especially the outbreak of cyanobacteria have become a worldwide environmental problem.Microcystis aeruginosa produces cyclic tetrapeptidemicrocystin,which can cause massive death of aquatic organisms,aquatic ecology systembalance destruction,and the toxin can affect human health through the food chain.Seek aecological safety algal inhibiting method is one of the key problems to be solved in the fieldof environmental science and engineering.Higher plants allelochemicals has great potentialin eutrophication water algae control.At present,the source and extraction of higher plantallelochemicals have some problems,such as the residue of secondary pollution.APMP pulping process has a small amount of chemicals,which has small destruction for organic compounds in the plant,and the current process of the allelochemicals obtaining is similar.In this paper,we studied the feasibility of extracting the higher plant species from eucalyptus APMP effluents,and applied to the control of the algae,exploring new sources of higher plant allelochemicals and solve residue problems in allelochemicals extraction.In this paper,different organic solvents were used to extract allelochemicals from eucalyptus APMP effluents,and be applied to the study of inhibition on Microcystis aeruginosa growth.This can solve the problem of the source of allelochemicals,and reduce the biological toxicity and organic matter load,improving the efficiency of biological treatment of wastewater.This thesis research eucalyptus pre-impregnated wastewater and APMP effluents,with different solvent extraction and preliminary study on the inhibitory effect,and enterprise production APMP wastewater extracts and study on the effect of different concentrations of allelochemicals on the growth of Microcystis aeruginosa.The allelochemicals of homemade APMP pre-impregnated wastewater were extracted and analyzed by the mean of ethyl acetate and methyl tert butyl ether extraction.The extraction rate of ethyl acetate was 174mg/L,and the extraction rate of methyl tert butyl ether was 88mg/L;the results showed that there were 32 kinds of organic extracts of ethyl acetate,29 kinds of organic extracts of methyl tert butyl ether,which has 21 kinds of the same organic compounds in the extract,accounted for 52.5%of all organisms.The organic acids were the main organic extraction in the two solvents,which accounted for 55%and 66%respectively.The study found that the inhibitory effect was not significant about low concentrations of allelochemicals,but 50 mg/L and 100 mg/L of algal inhibiting effect is obvious,at about 25%-30%.The allelochemicals of homemade APMP effluents were extracted by five organic solvents,which find that the extraction rate was correlated with the solvent polarity.The higher the polarity of organic solvent,the higher the rate of extraction.Extract yield of pulping wastewater was higher than the pre-impregnated waste water.Extract component analysis showed that:different organic solvents extracted allelochemicals have the same kind of organic matter,mainly divided into organic acids,alcohols,amines,esters and phenols,although the relative amounts of organic matter are different.The organic acids in the extracts were the largest proportion.The inhibitory of Microcystis aeruginosa study found that self-pulping wastewater algal extract more effective than pre-impregnated waste,and lower concentrations of allelochemicals would have a significant effect algal,especially 100mg/L concentration of allelochemicals inhibition efficiency was nearly 80%and have a significant role in the killing.Inhibiting effect of enterprise production APMP pulping wastewater were observed.The 50 mg/L inhibition rate was 37.84%,100 mg/L inhibition rate reached 47.82%.Using five solvents to extract allelochemicals and inhibit Microcystis aeruginosa,it was found that the 50mg/L and 100mg/L concentrations of the inhibition of Microcystis aeruginosa was the same,and the inhibition rate was basically in 15%-30%,although the extraction yield of different solvent extracts was different.It is proved that using organic solvent to extract allelochemicals in APMP effluents is a feasible method.Through different sources and different solvents extraction wastewater allelochemicals on algal inhibiting effect,the study found the different concentrations of allelochemicals algal inhibiting effect is similar to the conventional method to obtain higher plant allelochemicals algal inhibiting effect,which is characterized by promotion in lower concentration and inhibition in higher concentration.It is proved that the method is feasible to obtain the allelochemicals from APMP effluents by organic extraction.